cerebrovascular and trauma

Question 1

what is cerebral oedema

Answer 1

Excess accumulation of fluid in the brain parenchyma

Question 2

2 types of cerebral oedema

Answer 2

vasogenic
* disruption of BBB with trauma
* -> free movement of fluid
* -> oedema (endothelial lining with tight junctions, very regulated transfer of fluid across this)

cytotoxic
* secondary to cellular injury e.g. hypoxia/ ischemia
* -> kill cells that release fluid into the parenchyma
* -> hypoxic and ischemic damage

Result is raised intracranial pressure

Astrocyte feet keeping BBB in tact – receptors aquaporin 4 keeps water balance Change in normal water balance CSF across the ventricular wall disrupt the fluid balance across the wall

Question 3

macroscopic brain and CT of cerebral oedema

Answer 3

Sulci are pushed together
Cant see into the gyri
Oedematous brain
Lost all definition of sulci and gyri

Question 4

summarise the path of CSF

Answer 4

Lateral ventricle have chorid plexus – make CSF – pass into 3rd – down cerebral aqueduct – into 4th – some down central canal in spinal cord but most bathes brain in subarachnoid space
Ultimately resorbed into superior saggital sinus through arachnoid granulation

Question 5

what is non-communicating hydrocephalus

Answer 5

obstruction of flow of CSF
mostly in cerebral aqueduct
in neonates - choroid plexus blocks the flow

Rx
* Can bypass – catheter into ventricle – drain into the abdomen
* Can knock out floor of 3rd ventricle to allow CSF straight into subarachnoid space

Question 6

what is communicating hydrocephalus

Answer 6

no obstruction but problems with reabsorption of CSF into venous sinuses

Question 7

normal ICP

Answer 7

7-15mmHg for supine adult

Question 8

Consequences of raised ICP

Answer 8

can be due to space occupying lesions, oedema or both
because of: Unyielding bony wall of skull and inflexible dural folds, raised ICP->
Herniation of brain structures

Question 9

types of brain herniation

Answer 9

Subfalcine – brain tissue pushed under falcine cerebri

Can herniate medial temporal lobe into the posterior fossa - uncle herniation/transtentorial herniation

Tonsillar herniation – contents of posterior fossa into foramen magnum – fatal

Question 10

definition of a stroke

Answer 10

clinical syndrome characterised by rapidly developing clinical symptoms and/or signs of focal, and at times global loss of cerebral function, with symptoms lasting more than 24 hours or leading to death, with no apparent cause other than that of vascular origin

note: This definition includes stroke due to cerebral infarction, primary intracerebral haemorrhage, intraventricular haemorrhage and most cases of subarachnoid haemorrhage
It excludes subdural haemorrhage, epidural haemorrhage, intracerebral haemorrhage (ICH) or infarction caused by infection or tumour

Question 11

what is a TIA

Answer 11

warning stroke
caused by a clot
<5mins
no permanent injury to brain
1/3 of those with TIA get significant infarct within 5 years - need to determine what the cause of risk is

Question 12

summarise Non-traumatic intra-parenchymal haemorrhage

Answer 12

haemorrhage into parenchyma
due to rupture of small intraparenchymal vessel
most common in basal ganglia
hypertension responsible in >50%
Can get small bleeds in basal ganglia – called lacuna infaracts or bleed – may not have an avert clinical effect – may not be sx – because compensated for elsewhere

Question 13

sx of Non-traumatic intra-parenchymal haemorrhage

Answer 13

severe headache,
vomiting,
rapid loss of consciousness,
focal neurological signs

Question 14

summarise ateriovenous malformation

Answer 14

can occur anywhere in CNS
Blood straight from arterial to venous
Don’t supply the local tissues very well
Can rupture

sx between 2nd adn 5th decade
high pressure -> massive bleeding - surgical emergency
seen on angiography
high morbidity and mortality

Question 15

sx of arteriovenous malformation

Answer 15

haemorrhage,
seizures,
headache,
focal neurological deficits

Question 16

treatment of AVM

Answer 16

rx - surgery, embolization, radiosurgery

Question 17

Answer 17

AVM

Question 18

Answer 18

AVM
Massive vessels – not much brain tissue

Question 19

what is a cavernous angioma

Answer 19

Well-defined malformative lesion composed of closely packed vessels with no parenchyma interposed between vascular spaces

ie cavity surrounded by vessels
Congenital inherited malformation of the vasculature

Question 20

features of a cavernous angioma

Answer 20

found anywhere in CNS
sx after 50yrs
pathogenesis unknown
sx - headache, seizures, focal deficits, haemorrhage
Low pressure – recurrent bleeds

Question 21

rx of cavernous angioma

Answer 21

Rx: surgery – unless in an area that cannot be approached surgically

Question 22

Answer 22

cavernous angioma

Question 23

what is a subarachnoid haemorrhage and the cause

Answer 23

rupure of berry aneurysm - weakness of vessel wall
80 % - internal carotid artery bifurcation, 20% occur within the vertebro-basilar circulation
30% of pts have multiple aneurysms
Greatest risk of rupture when 6-10mm diameter

Question 24

sx and px of subarachnoid haemorrhage

Answer 24

sudden onset of severe headache (thunderclap),
vomiting,
loss of consciousness
Poor Px

Question 25

Answer 25

SAH

Question 26

Answer 26

SAH - Blood around the brainstem and the base of the brain

Question 27

treatment of cerebral aneurysms

Answer 27

endovascular treatment - coils Aneurysms found because have a scan for something else Neuroradiologists through femeral – fill aneurysm with coil Risk of rupture during surgery is low

Question 28

what is infarction

Answer 28

Tissue death due to ischemia – lack of blood

Question 29

cause of strokes by infartion

Answer 29

commonest form of strokes atherosclerosis is main cause - clots travel and block smaller vessels atherosclerosis is often near carotid bifurcation or in basilar artery Other cause - emboli (intracerebral arteries) eg air - embolic occlusion usually happen in middle cerebral arteries RFs - HTN, dm, smoking a) Focal cerebral ischaemia: defined vascular territory b) Global cerebral ischaemia: systemic circulation fails – cardiac problems - not getting blood to brain on regular basis

Question 30

what are the vascular territories

Answer 30

MCA – lateral and subcortical Anterior – all the way to posterior junction Posterior – occipital and inferior temporal

Question 31

which artery is blocked

Answer 31

middle cerebral

Question 32

differentiate between infarct and haemorrhage

Answer 32

Question 33

epidemiology of traumatic brain injury

Answer 33

single biggest cause of death in <45s high morbidity

Question 34

different types of head trauma

Answer 34

Non-missile and missile Non-missile acceleration/deceleration rotation RTA, falls and assaults Focal or diffuse

Question 35

summarise head fractures

Answer 35

Fissure fractures often extend into base of skull May pass through middle ear or anterior cranial fossa Otorrhea or rhinorrhea Infection risk

Question 36

what are contusions

Answer 36

Brain in collision with skull Surface “bruising” If pia mater torn, then becomes laceration Lateral surfaces of hemispheres, inferior surfaces of frontal and temporal lobes Coup or contrecoup

Question 37

summarise diffuse axonal injury

Answer 37

Occurs at moment of injury Shear & tensile forces affecting axons Commonest cause of coma (when no bleed) Midline structures particularly affected e.g. corpus callosum, rostral brainstem and septum pellucidum